1. Technical Field
The present invention relates to ink jet recorders.
2. Related Art
Ink jet recorders perform recording of data such as images on recording media by ejecting fine ink droplets through nozzles of an ink jet recording head. Such ink jet recorders have various structures in accordance with the types and sizes of the recording media used.
For example, JP-A-2012-45909 discloses a so-called serial ink jet recorder. A serial ink jet recorder has a head which is movable in a first direction (the width direction of the recording surface of a recording medium), and performs recording of images by moving the recording medium in a second direction intersecting with the first direction while reciprocating the head in the first direction.
JP-A-2010-264624 discloses a flat-bed ink jet recorder. A flat-bed ink jet recorder has, for example, a panel configured to fix a recording medium, and a head which is movable in a first direction of the recording surface of the recording medium (the width direction of the recording medium) and in a second direction intersecting with the first direction. Images are recorded on the fixed recording medium while the head is moved in the first direction and in the second direction. In most cases, such flat-bed ink jet recorders are used for the recording on hard, heavy and frequently large-sized recording media such as glass sheets, acrylic sheets and metal sheets.
On the other hand, UV curable inks are widely used in ink jet recording on such hard and heavy recording media because of their excellent weather resistance and water resistance. Ink jet recorders which record images with UV curable inks are usually equipped with an illuminator for curing the inks deposited on the recording media. For example, JP-A-2010-23285 discloses a flat-bed UV (UV curable) ink jet recorder in which a UV illumination device is mounted on a mobile member (such as a carriage) together with a printing head.
Such flat-bed ink jet recorders described above sometimes have a mobile unit which is movable at least in the second direction, and the head is mounted on the mobile unit to attain movability in the second direction.
On the other hand, ink cartridges (containers) for supplying inks to the head are often connected to the head via supply tubes. In such cases, the length of the supply tubes is preferably as short as possible because the increase in the length of the supply tubes tends to raise the probability of problems such as the entry of air and the increase in the amount of precipitates of ink components. In order to reduce the length of supply tubes, ink cartridges are sometimes mounted on the mobile unit similarly to the head.
In the case where an ink cartridge mounted on a mobile unit has run out of the ink during recording of images, the recording of images has to be interrupted for the exchange of ink cartridges. When the recording is resumed, however, it is often encountered that the colors of the images are different between before and after the resumption as well as that the mobile unit is misaligned during the exchange of ink cartridges, resulting in unsatisfactory images. Such failures of image recording cause a significant loss particularly in the recording with a flat-bed ink jet recorder because this type of recording usually involves expensive materials (for example, recording media such as acrylic sheets, and UV curable inks).
Meanwhile, UV curable inks exhibit high viscosity ascribed to the components (for example, polymerizable compounds) and consequently have a difficulty in being ejected through a recording head at times. Thus, the UV curable inks are heated to lower the viscosity to a level suited for ejection before the inks are ejected through a recording head. For example, such heating of UV curable inks is performed with heating units having a heater or the like which are disposed in, for example, the recording head, the containers containing the UV curable inks, and the ink channels connecting the containers to the recording head.
On the other hand, the flat-bed ink jet recorder described above sometimes has a mobile unit which is movable in the second direction (the direction intersecting with the width direction of the recording surface of a recording medium), and the head is mounted on the mobile unit to attain movability in the second direction. In this case, it is preferable that the mobile unit be lightweight in order to remedy the load on devices such as a motor driving the mobile unit.
However, the weight of the mobile unit tends to be increased, particularly when UV curable inks are used, because components such as the aforementioned UV illumination device and ink containers are often mounted on the mobile unit in addition to the recording head. In such cases, further installation of the heating unit in the mobile unit significantly increases the load on devices associated with the mobile unit.